[Ron61]

Per the new registry the first two coil spring Cobras were initially given on paper the CSX #s 2701 & 2702. But then it was decided that the coil spring cars would be the CSX 3XXX series and the first two chassis were stamped CSX 3001 & CSX 3002.
From Registry:

On CSX3002, the rear body work and front fender flares were actually carried over from the FIA and USRRC competition roadsters, but it had standard ( Not Cut Back ) doors. It also had a standard 289-style grill and nose, and a 289 style forward braced roll bar. Two-inch wide strips of sheet aluminum were sectioned into the top contour of the fenders to allow the body to fit over the new, wider coil spring chassis.

Ron